650
32072H–AVR32–10/2012
AT32UC3A3
For instance, if NBTRANS is three (three transactions per micro-frame), if only the first IN token
(among 3) is well received by the USBB, then the two last banks will be discarded.
27.7.2.18
CRC error
This error exists only for isochronous OUT endpoints. It set the CRC Error Interrupt (CRCERRI)
bit in UESTAn, what triggers an EPnINT interrupt if the CRC Error Interrupt Enable (CRCERRE)
bit is one.
A CRC error can occur during OUT stage if the USBB detects a corrupted received packet. The
OUT packet is stored in the bank as if no CRC error had occurred (RXOUTI is set).
27.7.2.19
Interrupts
There are two kinds of device interrupts: processing, i.e. their generation is part of the normal
processing, and exception, i.e. errors (not related to CPU exceptions).
Global interrupts
The processing device global interrupts are:
The Suspend (SUSP) interrupt
The Start of Frame (SOF) interrupt with no frame number CRC error (the Frame Number
CRC Error (FNCERR) bit in the Device Frame Number (UDFNUM) register is zero)
The Micro Start of Frame (MSOF) interrupt with no CRC error.
The End of Reset (EORST) interrupt
The Wake-Up (WAKEUP) interrupt
The End of Resume (EORSM) interrupt
The Upstream Resume (UPRSM) interrupt
The Endpoint n (EPnINT) interrupt
The DMA Channel n (DMAnINT) interrupt
The exception device global interrupts are:
The Start of Frame (SOF) interrupt with a frame number CRC error (FNCERR is one)
The Micro Start of Frame (MSOF) interrupt with a CRC error
Endpoint interrupts
The processing device endpoint interrupts are:
The Transmitted IN Data Interrupt (TXINI)
The Received OUT Data Interrupt (RXOUTI)
The Received SETUP Interrupt (RXSTPI)
The Short Packet (SHORTPACKET) interrupt
The Number of Busy Banks (NBUSYBK) interrupt
The Received OUT isochronous Multiple Data Interrupt (MDATAI)
The Received OUT isochronous DataX Interrupt (DATAXI)
The exception device endpoint interrupts are:
The Underflow Interrupt (UNDERFI)